checkpatch complaint

checkpatch complaint

[Arend van Spriel]

checkpatch complains on code below and I must overlook something or
checkpatch gives a false negative/positive/whatever:

#define IFPTR(usb, idx)         ((usb)->actconfig->interface[(idx)])
#define IFALTS(usb, idx)        (IFPTR((usb), (idx))->altsetting[0])
#define IFDESC(usb, idx)        IFALTS((usb), (idx)).desc
#define IFEPDESC(usb, idx, ep)  \
	(IFALTS((usb), (idx)).endpoint[(ep)]).desc

checkpatch errors:
ERROR: Macros with complex values should be enclosed in parenthesis
#169: FILE: drivers/net/wireless/brcm80211/brcmfmac/usb.c:58:
+#define IFDESC(usb, idx)        (IFALTS((usb), (idx))).desc

ERROR: Macros with complex values should be enclosed in parenthesis
#170: FILE: drivers/net/wireless/brcm80211/brcmfmac/usb.c:59:
+#define IFEPDESC(usb, idx, ep)  ((IFALTS((usb),
(idx))).endpoint[(ep)]).desc

Any ideas? I tried extra parenthesis around IFALTS but that does not
resolve it.

Gr. AvS

Re: checkpatch complaint

[Joe Perches]

On Wed, 2012-02-08 at 21:51 +0100, Arend van Spriel wrote:
> checkpatch complains on code below and I must overlook something or
> checkpatch gives a false negative/positive/whatever:
> 
> #define IFPTR(usb, idx)         ((usb)->actconfig->interface[(idx)])
> #define IFALTS(usb, idx)        (IFPTR((usb), (idx))->altsetting[0])
> #define IFDESC(usb, idx)        IFALTS((usb), (idx)).desc
> #define IFEPDESC(usb, idx, ep)  \
> 	(IFALTS((usb), (idx)).endpoint[(ep)]).desc
> 
> checkpatch errors:
> ERROR: Macros with complex values should be enclosed in parenthesis
> #169: FILE: drivers/net/wireless/brcm80211/brcmfmac/usb.c:58:
> +#define IFDESC(usb, idx)        (IFALTS((usb), (idx))).desc
> 
> ERROR: Macros with complex values should be enclosed in parenthesis
> #170: FILE: drivers/net/wireless/brcm80211/brcmfmac/usb.c:59:
> +#define IFEPDESC(usb, idx, ep)  ((IFALTS((usb),
> (idx))).endpoint[(ep)]).desc
> 
> Any ideas? I tried extra parenthesis around IFALTS but that does not
> resolve it.

I think the entries should be surround by ()
I think it's reasonable too.

I tried:

$ cat cp.c
#define IFPTR(usb, idx)		((usb)->actconfig->interface[(idx)])
#define IFALTS(usb, idx)	(IFPTR((usb), (idx))->altsetting[0])
#define IFDESC(usb, idx)	(IFALTS((usb), (idx)).desc)
#define IFEPDESC(usb, idx, ep)	((IFALTS((usb), (idx)).endpoint[(ep)]).desc)

$ ./scripts/checkpatch.pl -f cp.c
total: 0 errors, 0 warnings, 5 lines checked

cp.c has no obvious style problems and is ready for submission.

Re: checkpatch complaint

[Guenter Roeck]

On Wed, Feb 08, 2012 at 06:42:14PM -0500, Joe Perches wrote:
> On Wed, 2012-02-08 at 21:51 +0100, Arend van Spriel wrote:
> > checkpatch complains on code below and I must overlook something or
> > checkpatch gives a false negative/positive/whatever:
> > 
> > #define IFPTR(usb, idx)         ((usb)->actconfig->interface[(idx)])
> > #define IFALTS(usb, idx)        (IFPTR((usb), (idx))->altsetting[0])
> > #define IFDESC(usb, idx)        IFALTS((usb), (idx)).desc
> > #define IFEPDESC(usb, idx, ep)  \
> > 	(IFALTS((usb), (idx)).endpoint[(ep)]).desc
> > 
> > checkpatch errors:
> > ERROR: Macros with complex values should be enclosed in parenthesis
> > #169: FILE: drivers/net/wireless/brcm80211/brcmfmac/usb.c:58:
> > +#define IFDESC(usb, idx)        (IFALTS((usb), (idx))).desc
> > 
> > ERROR: Macros with complex values should be enclosed in parenthesis
> > #170: FILE: drivers/net/wireless/brcm80211/brcmfmac/usb.c:59:
> > +#define IFEPDESC(usb, idx, ep)  ((IFALTS((usb),
> > (idx))).endpoint[(ep)]).desc
> > 
> > Any ideas? I tried extra parenthesis around IFALTS but that does not
> > resolve it.
> 
> I think the entries should be surround by ()
> I think it's reasonable too.
> 
> I tried:
> 
> $ cat cp.c
> #define IFPTR(usb, idx)		((usb)->actconfig->interface[(idx)])
> #define IFALTS(usb, idx)	(IFPTR((usb), (idx))->altsetting[0])
> #define IFDESC(usb, idx)	(IFALTS((usb), (idx)).desc)
> #define IFEPDESC(usb, idx, ep)	((IFALTS((usb), (idx)).endpoint[(ep)]).desc)
> 
> $ ./scripts/checkpatch.pl -f cp.c
> total: 0 errors, 0 warnings, 5 lines checked
> 
> cp.c has no obvious style problems and is ready for submission.
>
Hi Joe,
 
different example, same message:

ERROR: Macros with complex values should be enclosed in parenthesis
#339: FILE: hwmon/ltc4245.c:339:
+#define LTC4245_ALARM(name, mask, reg) \
+       static SENSOR_DEVICE_ATTR_2(name, S_IRUGO, \
+       ltc4245_show_alarm, NULL, (mask), reg)

and:

ERROR: Macros with complex values should be enclosed in parenthesis
#585: FILE: hwmon/pc87360.c:585:
+#define VIN_UNIT_ATTRS(X) \
+       &in_input[X].dev_attr.attr,     \
+       &in_status[X].dev_attr.attr,    \
+       &in_min[X].dev_attr.attr,       \
+       &in_max[X].dev_attr.attr,       \
+       &in_min_alarm[X].dev_attr.attr, \
+       &in_max_alarm[X].dev_attr.attr

and:

ERROR: Macros with multiple statements should be enclosed in a do - while loop
#291: FILE: hwmon/sis5595.c:291:
+#define show_in_offset(offset)                                 \
+static SENSOR_DEVICE_ATTR(in##offset##_input, S_IRUGO,         \
+               show_in, NULL, offset);                         \
+static SENSOR_DEVICE_ATTR(in##offset##_min, S_IRUGO | S_IWUSR, \
+               show_in_min, set_in_min, offset);               \
+static SENSOR_DEVICE_ATTR(in##offset##_max, S_IRUGO | S_IWUSR, \
+               show_in_max, set_in_max, offset);

Those are all pretty common in the hwmon subsystem and all quite annnoying.
Other than labeling them as "false positive", I have no idea what to do about it.
Sure, we could replace all the macros with immediate code, but that doesn't sound
very compelling. If you have an idea, please let me know.

Thanks,
Guenter

Re: checkpatch complaint

[Dan Carpenter]

[-- Attachment #1: Type: text/plain, Size: 1792 bytes --]

On Wed, Feb 08, 2012 at 03:42:14PM -0800, Joe Perches wrote:
> On Wed, 2012-02-08 at 21:51 +0100, Arend van Spriel wrote:
> > checkpatch complains on code below and I must overlook something or
> > checkpatch gives a false negative/positive/whatever:
> > 
> > #define IFPTR(usb, idx)         ((usb)->actconfig->interface[(idx)])
> > #define IFALTS(usb, idx)        (IFPTR((usb), (idx))->altsetting[0])
> > #define IFDESC(usb, idx)        IFALTS((usb), (idx)).desc
> > #define IFEPDESC(usb, idx, ep)  \
> > 	(IFALTS((usb), (idx)).endpoint[(ep)]).desc
> > 
> > checkpatch errors:
> > ERROR: Macros with complex values should be enclosed in parenthesis
> > #169: FILE: drivers/net/wireless/brcm80211/brcmfmac/usb.c:58:
> > +#define IFDESC(usb, idx)        (IFALTS((usb), (idx))).desc
> > 
> > ERROR: Macros with complex values should be enclosed in parenthesis
> > #170: FILE: drivers/net/wireless/brcm80211/brcmfmac/usb.c:59:
> > +#define IFEPDESC(usb, idx, ep)  ((IFALTS((usb),
> > (idx))).endpoint[(ep)]).desc
> > 
> > Any ideas? I tried extra parenthesis around IFALTS but that does not
> > resolve it.
> 
> I think the entries should be surround by ()
> I think it's reasonable too.
> 

No.  That's not reasonable.  The other code is:
A) perfectly fine
B) nicer to look at

We already have newbies running checkpatch.pl -f against the kernel
source and sending bogus patches that make the code uglier.  I've
tried to fight back against checkpatch patches before where they
make the code worse, but it's just overwhelming.  I don't like to
be the bad guy to tell newbies that they are sending bad patches
when actually the Official Kernel Checkpatch tool said they should
send it.  We're causing everyone pain for no reason.

regards,
dan carpenter

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 836 bytes --]

Re: checkpatch complaint

[Bernd Petrovitsch]

On Mit, 2012-02-08 at 21:05 -0800, Guenter Roeck wrote:
> On Wed, Feb 08, 2012 at 06:42:14PM -0500, Joe Perches wrote:
> > On Wed, 2012-02-08 at 21:51 +0100, Arend van Spriel wrote:
> > > checkpatch complains on code below and I must overlook something or
> > > checkpatch gives a false negative/positive/whatever:
> > > 
> > > #define IFPTR(usb, idx)         ((usb)->actconfig->interface[(idx)])
> > > #define IFALTS(usb, idx)        (IFPTR((usb), (idx))->altsetting[0])
> > > #define IFDESC(usb, idx)        IFALTS((usb), (idx)).desc
> > > #define IFEPDESC(usb, idx, ep)  \
> > > 	(IFALTS((usb), (idx)).endpoint[(ep)]).desc
> > > 
> > > checkpatch errors:
> > > ERROR: Macros with complex values should be enclosed in parenthesis
> > > #169: FILE: drivers/net/wireless/brcm80211/brcmfmac/usb.c:58:
> > > +#define IFDESC(usb, idx)        (IFALTS((usb), (idx))).desc
> > > 
> > > ERROR: Macros with complex values should be enclosed in parenthesis
> > > #170: FILE: drivers/net/wireless/brcm80211/brcmfmac/usb.c:59:
> > > +#define IFEPDESC(usb, idx, ep)  ((IFALTS((usb),
> > > (idx))).endpoint[(ep)]).desc
> > > 
> > > Any ideas? I tried extra parenthesis around IFALTS but that does not
> > > resolve it.

You probably did it wrong. Sent the next time what you *really* did and
not only description .....

> > I think the entries should be surround by ()
> > I think it's reasonable too.
> > 
> > I tried:
> > 
> > $ cat cp.c
> > #define IFPTR(usb, idx)		((usb)->actconfig->interface[(idx)])
> > #define IFALTS(usb, idx)	(IFPTR((usb), (idx))->altsetting[0])
> > #define IFDESC(usb, idx)	(IFALTS((usb), (idx)).desc)
> > #define IFEPDESC(usb, idx, ep)	((IFALTS((usb), (idx)).endpoint[(ep)]).desc)
> > 
> > $ ./scripts/checkpatch.pl -f cp.c
> > total: 0 errors, 0 warnings, 5 lines checked
> > 
> > cp.c has no obvious style problems and is ready for submission.
> >
> Hi Joe,
>  
> different example, same message:
> 
> ERROR: Macros with complex values should be enclosed in parenthesis
> #339: FILE: hwmon/ltc4245.c:339:
> +#define LTC4245_ALARM(name, mask, reg) \
> +       static SENSOR_DEVICE_ATTR_2(name, S_IRUGO, \
> +       ltc4245_show_alarm, NULL, (mask), reg)

*eg* Make it one (long) line. IMHO this is a prototype example to ignore
the 80-column limit.

I haven't looked the the reg-exps (or the code in `checkpatch`) but
either make `checkpatch` recognize the "\" at the end of lines and merge
the lines before doing these checks (since they apparently assume that
the complete macro definition is on one line) or allow "\\\n" within the
reg-exps.

> and:
> 
> ERROR: Macros with complex values should be enclosed in parenthesis
> #585: FILE: hwmon/pc87360.c:585:
> +#define VIN_UNIT_ATTRS(X) \
> +       &in_input[X].dev_attr.attr,     \
> +       &in_status[X].dev_attr.attr,    \
> +       &in_min[X].dev_attr.attr,       \
> +       &in_max[X].dev_attr.attr,       \
> +       &in_min_alarm[X].dev_attr.attr, \
> +       &in_max_alarm[X].dev_attr.attr
[...]
> Other than labeling them as "false positive", I have no idea what to do about it.
> Sure, we could replace all the macros with immediate code, but that doesn't sound
> very compelling. If you have an idea, please let me know.

Given that the above gives after the preprocessor the desired results:
Add special comments (like `indent` allows to disable it temporarily) so
that checkpatch doesn't complain about these macros.
Yes, that can be abused but review should catch that. And newbies won't
see false positives.
Listing the to-be-ignored #define's in `checkpatch` (or some external
file) or enhancing it with some "known false positives, do not emit
*that* warning there" is also a maintenance burden (hmm, how often do
they change?).

	Bernd
-- 
Bernd Petrovitsch                  Email : bernd@petrovitsch.priv.at
                     LUGA : http://www.luga.at